LIMULUS-LYSATE ENDOTOXIN ASSAY AS A TEST OF MICROBIAL QUALITY OF GROUND BEEF

The Limulus lysate test (LLT) for endotoxin assay was an excellent, simple and rapid test of microbial quality of refrigerated ground beef. In fresh ground beef held at 5.degree. C for 7-12 days, LLT titers increased from 102-105 and correlated very highly with extract-release volume (ERV) data and total viable gram negative counts at 5.degree. and 30.degree. C. The LLT was negative for fresh beef containing low numbers of bacteria and on aged beef in the absence of increasing numbers of gram negative bacteria. Of 14 gram negative meat isolates, all gave a positive LLT while none of 8 miscellaneous gram positive bacteria did. The use of this test provides objective information on the microbial quality of fresh refrigerated ground mets in 1 h. A 0.1 ml inoculum from a 103 dilution of good quality ground beef should produce a negative lysate test and thus should serve as an additional rapid screening test of meat microbial quality.